Last night I started transferring all my data from my 2010 MBA to my new 2012 MBA using Migration Ass't., via usb - ethernet -Thunderbolt adaptors. It started OK, and said "remaining time 24 hours". This morning, it said 6+ hours, then this afternoon went to 31 hours. For the last 4 hours it has been stuck at 25 hours. If I disconnect the two MBA's to try and start again, is there a likelihood of corrupting my original data? What would be the best way to stop the transfer? as I can't see any "Cancel" button.